Anyone who has experience doctors too much knows you do need to do homework if you want to know if what they're doing is the right thing, especially if what they're doing isn't working or is making things worse. As with any product sold by anyone trying to maximize their income, and doctors are no different most of the time, a lot of what the sellers of that product know is provided by the manufacturer, not an independent source. So it doesn't hurt to check up on what doctors do to and for you. But obsessing over it, obsessing over anything, to the point where it becomes your whole life and your health starts suffering is taking it too far. But she's scared and has started grieving before her father has even died. Cancer is a really tough illness to deal with because it takes a long time usually to finish its work. I went through this with my mother. So I get why she would want to make sure the doctors are doing the best things. I doubt she'll find that information on the internet, as it's a hard place to learn medicine on from scratch, obviously, but I'd give her that space. But make sure you let her know to keep her life in balance so she can be there for her father and for you, too. If she stays this frightened by the prospect of losing her Dad, therapy might be something she needs to do, especially since, as I said, cancer can take a long time to do its work. Even when it's "gone" it isn't really gone, so at some point you either come to terms with it as a part of life or you lose a part of yourself, too.